Feral pests taking toll on outback animals

Scientists working in the Simpson Desert in far west Queensland say an explosion in feral animal numbers is threatening native mammals.

A team from the University of Sydney has been studying the desert ecosystems for the past 20 years and has just returned from a field trip 150 kilometres west of Bedourie.

Professor Chris Dickman says it trapped very few small mammals and that is a concern.

"The feral cats just seem to have exploded - there are signs of feral cats everywhere," he said.

"Their scratching, droppings are everywhere, you see the footprints on the sand dunes.

"When you break open some of the cat droppings, the droppings are full of small mammal hairs - rat hairs, small mouse hairs.

"They are really getting stuck into some of the small mammals."

Feral pigs have also been reported in the Simpson Desert region.

Professor Dickman says it appears the pigs have been moving down river systems from the north.

"We haven't seen it before in 20-odd years of working in the region," he said.

"It looks as if there is more evidence of feral pigs moving into some of the drier country.

"If the pigs are now coming in and following up where the foxes and cats have already reduced their numbers, and then the feral pigs are reducing their shelters further, it is possible we are going to lose some of these species over very large areas of their ranges."

Professor Dickman says the feral pests have thrived during ideal conditions and native animals are at risk.

"That puts a real crunch period in place where there is very intense per capita predatation on the small mammals," he said.

"We think it can be so intense that you can get local losses of species for periods of many years.

"I guess if this sort of thing happens too frequently, then you can have regional losses of species for very long periods."

However, New Diamantina Mayor Geoff Morton says big numbers of pest animals are a normal part of the "boom and bust" cycle of the Channel Country.

Mr Morton, from Birdsville in far south-west Queensland, says state authorities tried to control feral pigs by aerial shooting last year but it was not overly successful.

"[The then-Department of Environment and Resource Management] DERM have already had a go eradicating them last year when the season was good, which was probably pork pie stuff because it was too hard to find a pig because there was water everywhere," he said.

"But 50 years of experience has taught me that the land will look after itself eventually, when it turns back to the more normal seasons.